Sun Java packages have been dropped from Ubuntu 10.04 LTS from the Multiverse section of Ubuntu archive. Ubuntu team is encouraging users to use OpenJDK instead of Sun JDK/JRE but still if you want to install Sun JDK on your Ubuntu then here is the solution for the same. OpenJDK Appearing – No Sun Java in Synaptic As per the release note of Ubuntu 10.04 LTS, Ubuntu users can have Sun Java by executing the following piece of code on the command line. add-apt-repository "deb http://archive.canonical.com/ lucid partner" This will install sun-java6 packages from Canonical Partner Repository. Enjoy Sun Java on Ubunu 10.04 Lucid.